Rows of holes are drilled alongside the boundaries of a PCB to produce plated half hole PCBs. When the holes have been through plated, the edges are pruned so the holes along the boundary are reduced in half. The edge of the PCB will look like the top of a plated, half hole PCB.
Many times, recesses are used for the simple task of linking adjacent boards. They also may also be included as a part of the board circuitry such as accessing parts on a daughter board.
An additional benefit of plated half holes is that it provides additional ways of connecting boards that are placed alongside the boundaries of the PCB, an area that is idle from the beginning. Plated half holes are primarily utilized in board-on-board connections, mainly when two circuit boards with dissimilar technologies need to be combined. It will look like the PCB has SMT pads at the base with vias in them and has been divided through the middle of the vias.
Plated half holes techniques can be used for stacking one board immediately on top of another board, with the following prerequisites:
Zero spacing or gap between the two boards
Electrical contacts are required, not just physical connection
It is better to ask a PCB fabrication house how they require the details of plated half holes PCBs. You can choose the most convenient ways as per the guidelines.
Plated half holes are economical connection techniques, which transform the board into a surface mount sub-assembly. They are frequently used as breakout circuits for fine-pitch SMD parts or on small radio or RF assemblies. Since they are plated and concave, these PCBs provide better landings for soldering. Their position on the boundaries of the board signifies that the surface mount parts or daughter board will mount flush on the motherboard surface. There will be no space for dust or moisture to gather once the unit is in place.
As per customer specifications, there is an additional cost for plated half holes PCB. The details can be obtained from the representatives of a PCB fabrication house.